I have a concurrent program of type "HOST" failing.
ORA-12545: Connect failed because target host or object does notexist
Usage: CONNECT <username> [AS SYSDBA|SYSOPER]
ORA-01017: invalid username/password; logon denied
unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus
From the app tier I was able to connect to the database using SQLPlus
Please check following MOS Notes:
Troubleshooting ORA-12545 / TNS-12545 Connect failed because target host or object does not exist (Doc ID 553328.1)